Method of manufacturing yeast fermented beverages



Dec. 6, 1938. I HEUSER 2,139,408

METHOD OF MANUFACTURING YEAST FERMENTED BEVERAGES Filed Jan. 50, 1956 2 sheets-sheet 1 @WMM/M H HEUSER 2,139,408

METHOD OF MANUFACTURING YEAS'I' FERMENTED BEVERAGES Dec. 6, 1938.

Filed Jan. 30, 1936 2 Sheets-Sheet 2 Patented Dee. c, 193s' U-NiTfEDfsTArEs PATENT OFFICE METHOD F MANUFACTURING YEAST FEBMENTED BEYERAGES Herman Heuser, Evanston, Ill.

Application January 30, 1936, Serial No. 61,627 1 claim. (ci ca -41) the beverage, whereby the characteristic tastev and flavor of the beverage produced during the yeast fermentation are increased.

Another object of my invention is to produce in the manufacture of yeast fermented beverages a yeast practlcally'free from foreign ferments and further also free from hop resins, in case of the manufactureof a yeast fermented hopped beverage, whereb/rit isl made possible to vomit the customary washing to purify the yeast, which washing-greatly weakens the yeast.

Afurther Object of my invention is to carry out the separation of the yeast from these bev# erages in a way that automatically produces an ample amount of yeast fit for use as pitching yeast. As is the customary practice, the yeast for example in the manufacture of ale is separated from the beverage by skimming it-from the surface of the beverage. Such skimming requires very much time and attention to obtain by it a sufficient quantity of yeast thatV is. flt for pitching. The limited amount of yeast separated from the wort in the customary manufacture of ale is the reason why vusually only V2 lb. of ale yeast is used for pitching the wort.

However, to use so little yeast for pitching lthe wort, delays the fermentation of the wort, whereby the .growth of foreign ferments in the wort is invited.v

The various objects of my invention are solved by my discovery that, when a yeast fermentable liquid body such as hopped wort pitched with yeast, is divided into an enclosed lower part and an enclosed upper part suitably communicating with` eachv other, the fermenting wort ows from the enclosed lower part of the wort to the enclosed upper part of the fermenting wort and back again into the lower part of the wort. The

flow of the fermenting wort greatly invigorates the yeast, whereby the characteristic taste and` flavor of the beverage are greatly increased; the now also separates theA yeast from the beverage in a much larger quantity and in much purer condition than usually isthe case, the separated yeast being substantially free from foreign ferments and hop resins, and being all fitted to serve as pitching yeast. The yeast a 5 white color instead of 4the customary dark gray color.

' An apparatus suited for carrying out my invention comprises a plate laid across an enclosed fermenter preferably in a horizontal position or in a slightly inclined position and tightly fitting to the walls ofthe fermenter, further a passageway connecting the top part of the lower compartment of the fermenter with the upper part of the upper compartment of the fermenter, and further a passageway connecting the lower part of the upper compartment with the lower part of the lower compartment. The passageway connecting the top part of the lower com` partment withthe upper part of the upper compartment is preferably a pipe reaching from anI opening in the plate upwards and the passage way connecting the lower part of the upper compartment with the lower part of the lower compartment is a pipe reaching froman opening in the plate downwards as illustrated in Fig. 1 of the drawings, the former pipe being termed by me the foam pipe, because the fermenting beverage `hows through the same mostly in the form of foam, andthe .latter pipe is termed by me the return flow pipe, because the foam-free beverage flows back through this pipe into the lower compartment. While a plurality of foam pipes may be employed, it is preferred to employ only one. This, when located in the center of the plate as shown in Fig. 1, Fig. 2 and Fig. 3 is provided with a removable hood tightly fitting by a `sleeve around the top of foam pipe, the hood preventing during the fermenting operation beverage from sputter- 4o ing from the top of the foam pipe into the openings of the-gas pipes emanating from the top of the fermenter. d

The foam pipe may be also located at or near the border of the plate with the return flow pipe k directly opposite on the border of the plate near the manhole door and yeast pipe-as shown in Fig. 4. This arrangement facilitates the removal of the yeast from the plate, because the plate is virtually free from any obstacle in the way of the scraping device employed by the operator working` from the manhole door to scrape the yeast from the plate to the yeast pipe.

There is produced in the fermenting beverage or the lower compartment a higher prelsure than in the fermenting beverage of the upper compartment because of the restricted escape through the foam pipe of the CO2 produced in the lower compartment, which furnishes the motive power for the now of the fermenting beverage.

In order to provide pressure in the lower compartment sufficient to make the fermenting beverage flow freely, the foam pipe must not be too wide, for then the CO2 will escape through lt without taking the beverage along. On the other hand it should not be too narrow, because then the pressure produced in the lower compartment will seriously restrict, stop, or reverse the flow through the iiow pipe.

If, for example, the proportion between the diameter of the foam pipe to that of the fermenter is of the order of 1 to 30 or 1 to 36 and the proportion between the diameter of the return-flow pipe to that of the fermenter is 1 to 54, satisfactory results will be obtained with a 108 inch plate and a depth of about seven feet of wort below it.

With 100 barrels of ale wort filling up the lower compartment up to the plate a good flow of the fermenting ale wort is obtained, when the foam pipe has an area of about 9 to 12 square inches and the return flow pipe has an area of 3.25 square inches. In proportion as the holding capacity of the lower compartment increases or decreases, so the area of the foam pipe and the area of the return flow pipe increases or decreases.

For the successful carrying out of my invention it is absolutely necessary that the fermenter be charged with the yeast fermentable liquid body so high that the plate is immersed in the liquid, the immersion may be so deep that the depth of the liquid in the upper compartment is as large as the depth of the liquid in the lower compartment as indicated in Fig. 3, but generally the depth of the liquid in the upper compartment will be about 10 to 25 percent of the depth of the liquid in the lower compartment, as indicated in Fig. 1, Fig. 2 and Fig. 4.

If the fermenter were only charged up to the plate or nearly up to the plate with the yeast fermentable liquid, there would be no flow of the liquid, there would be only an ejection of yeast during the yeast-coming-up period, that is, during the latter part of the fermentation, containing entrained liquid, in the case of the employment of top yeast as in the manufacture of ale, but in case of the employment of bottom yeast as in the manufacture of beer, there would not be even an ejection of 'yeast through the foam pipe.

The fermentation of the yeast fermentable liquid body may be carried out under an atmospheric pressure or under a super-atmospheric pressure on the liquid in the upper comartment, it being understood, of course, that the pressure in the fermenting liquid in the lower compartment is always higher than the pressure on the liquid in the upper compartment. The employment of a super-atmospheric pressure on the liquid in the upper compartment is preferred because it increases the taste and flavor or ester content of the beverage, and more effectually preserves the beverage and the yeast against infection by foreign ferments.

The fermenter may be of any suitable form, but round fermenters are preferable, because they stand a high pressure and being without corners they are readily kept clean. As to the height of the enclosed upper compartment of the fermenter, the same should be high enough to permit a man to attend to the cleaning in the same in an upright position.

In the following I will describe an apparatus suitable to carry out my invention:

Fig. 1 is an elevation, partly in section of a battery of fermenters. Figs. 2, 3 and 4 indicate similar views of modied fermenters. Fig. 1 indicates how the CO2-outlet of the fermenters in a fermenting room may be connected up to a CO2-main produced by the yeast fermentation of a bever-age into the atmosphere outside the plant. This arrangement for the disposal of the CO2 keeps the atmosphere of the fermenting room in good condition, whereby the customary danger to the health of the men working in the fermenting room is eliminated.

The fermenting apparatus, as shown in Fig. l, may consist of a cylindrical shell I2 preferably of steel welded to a steel top 5 and a steel bottom 6 and covered on the inside by asuitable varnish or enamel. The apparatus is divided by plate 9 into a lower compartment I and an upper compartment 8. Plate 9 is of metal, generally steel, preferably horizontally placed and welded tightly to the Wall I2.

A passageway Il is provided in the plate 9 through which foamy beverage flows from the lower compartment into the upper compartment. This pipe is placed on an opening in the center of plate 9. It should be so high as to reach above the beverage and foam level in the upper compartment. The pipe I0, reaching from the plate 9 deep into the lower compartment, prolVides a return-flow passageway through which the beverage, passed into the upper compartment as a foamy mass through the foam pipe II, flows back into the lower compartment after separation from entrained gas. 'I'he returnflow pipe Ill is placed near the border of plate 9, it is provided with a removable short headpiece I4 that is high enough to hold back the yeast that settles on plate 9. Pipe I6 provides a passageway reaching from plate 9 downward and out of the fermenter for the discharge of the yeast therefrom. This pipe is equipped at its upper terminal with a stopper I8 and at its lower terminal with a valve I`I. When the yeast is to be removed from plate 9, stopper I8 is taken out of the yeast pipe I6 and inserted into the return flow pipe I0, after the riser I4 has been taken out of the return flow pipe or the riser may be stoppered. It is preferred that the handle 46 of the stopper I8 be removable so as to provide no obstruction to removal of yeast.

Furthermore, the fermenting apparatus of Fig. 1 is equipped with a cooler I9 provided with a valve 20 for the inlet of the cooling medium, usually brine, and with an outlet 2| for its return to the cold brine supply (not shown). The fermenting apparatus is also equipped in the upper compartment 8 with an electric light 22 enclosed by a pressure proof glass casing 23 to provide the necessary light for the proper filling of the apparatus and for the removal of the yeast that has settled on the plate 9, after the fermented beverage has been removed from the fermenter. Further, the fermenting apparatus of Fig. l is provided with a pipe 25 controlled by valve 26 for the inlet and outlet .of the beverage, further with a thermometer 2'I and a trycock 28 and with a manhole door 29 in the lower compartment 1. A manhole door 30 in the upper compartmentA 8 permits an operator, after the fermented beverage has been removed from the fermenter, to remove 9,189,403 the yeast ,that has setued on plate s, through yeast pipe IS. 'I'he -fermenter is covered on the bottom'3 and on the side walls by a suitable insulating material such4v as cork. The top is preferably uninsulated.A

Further, the fermenting apparatus is equipped Vat its top i with a gas pipe 32 controlled -by valve 4pressure of say 3 to 'I pounds into the .atmosphere plate 9 to a depth say of about 15 to 20 percent` of the depth of the wort in the lower compart,`

33 connected `to `the gas main 34, which discharges the CO2 through a pressure valve in the form of a blow-oil valve 35 set at a relatively low outsidethe plant. I'he fermenting apparatus is l provided with pipe 36 equipped with valve 31 which terminates in the CO2 main 38 equipped with a pressure valve in the form of a blow-off valve 39 set at a'relatlvely high pressure'of say 15 to 30 pounds. yPipe 36 is `connected with pipe 46 controlled by valve 4 I for the` introduction of compressedgas to be used during the discharge of the fermented beverage from the fermenting apparatus. Pipe 36 is also provided with a pressure .gauge y42 for indicating the pressure in the ferinenting apparatus during'the fermentation of the beverage, the pressure in the apparatus during the discharge of the fermented-beverage from the fermenter being indicated by a pressure gauge not shown, which may be attached to the trycock 28 during the discharge of the fermented bever- In the following I will describe-a process suitable to carry out my invention in the manufacture of ale:

Hopped wort with a Balling indication ofsay y14 degrees and a temperature of say 60 F., aerated as usual and pitched with 1 to 11/2 pounds of thick-fluid ale yeast per barrel ofwort is run through valve 26 of pipe 25 into the fermenting apparatus of Fig. 1- with valve- II lopen for the` escape of air from the fermenter. When sufficlnt wort has been supplied to immerse the ment of the fermenter, for example, about seven feet, the flow' of the wortis stopped by closing valve 26, valve 4I being also closed, and fermentation permitted toQ proceed.

After the fermentation of the wort has commenced,v the wort owscontinuously and automatically from the lower .compartment 1 through foam pipe II into the upper compartment 8 and back again from the plate 9 through the return flow pipe I into the lower 'compartment 1. The worst flows upwards from' the lower compartment vtlfirough the foam pipe II as a foamy mass, and returns, `after separation of the gas, to the lower compartment through return flow pipe I0 as liquid. wort. The CO2 produced during the fermenta-l ltion of the wort passes through valve 33 of pipe az into the co2-main sa: from which u ladiecharged through blow-off valve 35, setlat pounds the atmosphere outbecomes larger, as long as the flow ofthe Wort continues. When the fermentation of the wort has been completed preferably to such an extent that the saccharomete indication of the samples taken at try-.cock28 do not vary anymore and that `means complete fermentation of the Wort, l then thefermented wort or ale is cooled to a tem` perature/,of say 34 to 36 F. by cooler I9, thecooled ale being preferably kept inthe fermenter, until it has sufficiently clarifled Thereupon, the clarified cooled ale is run out of the fermenter clarification in the storage tanks.

has begun its flow, a sedlwith a suiilcient gas pressure being kept on it by y means of compressed gas, preferably CO2. passing through pipe `I connected by a hose (not shown)l to the gas supply (not shown). The gas pressure should be' so high that the CO: present inthe beverage remains inthe beverage during its discharge from the fermenter. The beverage is pre#v pared for the market preferably without any storage. Thereupon, the ale is forthwith carbonated and filtered and putin the trade packages. Storing of the beverage is unnecessary, because of `the complete fermentation of the beverage and a sufliclent clarification of the beverage in the fermenter. In order to increase the C02 content of the beverageinthe fermenter to the market content,v valve 33 of pipe 32 is closed, before the' termen-'- tation of the wort has been entirely completed. This, by'keeping the CO2 produced in the fero it has been completely fermented, as can be seen,

when the Balling indication of the samples taken at trycock 28 do not vary anymore. Thereupon, the beverage is cooled to a temperature of say 34 to 36 F., and then vleft to clarify in the fermenter.

l After it hassuiiiciently clarified, the beverage is run from the fermenter under CO2 pressure 'to retain its CO2 content, and made-ready for the market .without customary storing, which would have no purpose, because the beverage, having been completely fermented and also clarified, does not require the customary after fermentation and This is a great advantage because of the growth of foreign ferments in and the absorption of air by the stored beverage which `occur in customary practice and `which deteriorate the taste-and flavor of the beverage.

After the beverage has been removed from the fermenter through valved'pipe 25, the yeast is removed fromplate 8. For this purpose the gas is first removed from the fermenter by valve 4I, the manhole door 30 is opened, the headpiece I4 is lifted out of the return flow pipe I0, and stopper I8 is put in its'place. The yeast is then scraped from the plate to the yeast pipe by means of a suitable wooden scraper and discharged through. valve I1 of yeast pipe I6 into a suitable .yeast receptacle.

During the fermentation the hop resins are rprecipitated on the walls of the upper compartment and-are thus removed from the beverage. 'I'his precipitation or sticking is apparently in large measure due to or'7 coincident with the breakdown of the foam.

` The empty fermenter is now cleaned, rst the upper compartment and then the lower com'- partment. v

The ale thus produced by the use of my invention is distinguished in that it is much richer in aleA taste and ale flavor; than the ale made by the customary methods and it is also unusuallyl pure in taste and flavor.

70 ,The yeast produced by the use of my invention ment. For this reason the yeast has a white color instead of the customary dark gray color.

The amount of ale yeast present after fermentation totals about 9 lbs. of thick fluid yeast per barrel of beverage, about 80 percent of this amount (all lit for pitching) being on the plate,

and about 20 percent of the yeast being on the bottom of the lower compartment. This is an entirely unexpected yeast yield particularly in view of the use of superatmospheric pressure, and

without the introduction of air during the fermentation, the introduction of air or oxygen having been carefully avoided. In the customary separation of yeast from ale by skimming, the amount obtained is about 35 to 40 percent of all the yeast produced and originally present inthe ale wort as pitching yeast and of this only a relatively small amount is iit for pitching, after it has been washed to free it from foreign ferments and hop resins.

The invention may be also successfully employed in the manufacture of bottom fermentation beverages such as beer. In order to produce a satisfactory flow of the fermenting wort during the beer fermentation from a bottom fermentation yeast, it is necessary to carry out the fermentation at a starting temperature about 10 to 12 F. higher than usually is the case, and in addition it is generally preferred to use also a larger amount of yeast for pitching the wort than usually is the case, generally about twice as large as the usual amount of one pound per barrel of Wort.

The invention may be also employed to great advantage in the manufacture of beverages made by yeast fermentation from fruit juices, such as for example grape juice and apple juice. The resulting beverage possesses, after its fermentation has been completed, an unusually rich wine taste and wine flavor. The fermenting fruit juice flows upward in the foam pipe mostly in the form of a liquid. When the fruit juice is pitched with cultivated wine yeast, then the amount of yeast that settles on the plate is about 70 percent of all the yeast that is produced during the fermentation of the fruit juice which is about 2 to 3 lbs. of thick iiuid yeast per 31 gallons of fruit juice.

As is plain, the flow of the beverage is the quintessence of my invention, which ow can be only obtained by immersing the plate in the beverage; it cannot be obtained by not immersing the plate in the beverage, that is to say byfilling up the fermenter with beverage only up to the plate as is the common practice. The flow of the beverage not only separates more yeast from the beverage than usually is the case, it also invigorates the yeast so that the yeast and the beverage are greatly improved and it also separates all the precipitated hop resins from the beverage and from the yeast, whereby a yeast free from hop resins is produced. It is due to the flow of the fermenting beverage that the yeast can be separated on the plate from beverages fermented by the bottom yeast such as beer in which the yeast always sinks to the bottom of the fermenter at the close of the fermentation.

The foregoing detailed description has been fil given for clearnessof understanding only, and no pleting the fermentation under a relatively high super-atmospheric pressure, whereby during the fermentation CO2 is generated from the liquid and forms a foamy mass including liquid, gas and yeast, passing the foamy mass autogenously by displacement into a secondary fermenting body of a liquid, separating liquid and yeast from the foam and continuously returning liquid to the primary fermenting body, the rate of passage of the foamy mass into the secondary body being correlated to the errnenting time so that the bulk of the yeast is passed into the secondary body.

HERMAN HEUSER. 

